Pricing of imperfect substitutes:The next flight is not the same flight

We investigate how airfares respond to changes in the fare of adjacent flights. Using a fixed effects regression on fares from Amsterdam to Geneva, we find flights that only differ in departure times to be weak substitutes. Fare-to-fare elasticities for imperfect substitute flights of different airlines are even smaller, implying weak competition between airlines on this specific route. If our findings hold for other routes as well, this will have implications for the analysis of price dispersion in civil aviation. It would imply that demand shocks for individual flights have small effects on prices of other flights. Demand volatility would then be likely to affect price dispersion on a route level and should be considered when analyzing price dispersion

Divergent mathematical treatments in utility theory

In this paper I study how divergent mathematical treatments affect mathematical modelling, with a special focus on utility theory. In particular I examine recent work on the ranking of information states and the discounting of future utilities, in order to show how, by replacing the standard analytical treatment of the models involved with one based on the framework of Nonstandard Analysis, diametrically opposite results are obtained. In both cases, the choice between the standard and nonstandard treatment amounts to a selection of set-theoretical parameters that cannot be made on purely empirical grounds. The analysis of this phenomenon gives rise to a simple logical account of the relativity of impossibility theorems in economic theory, which concludes the paper

Exploring the Origin of the Bering Sea: Initial Results of Cruise SO249-2 (17th July – 13th August 2016)

The Bering Sea is one of the largest marginal seas on Earth with still poorly understood origin and evolution. Cruise SO249-2 of the German research vessel Sonne explored the western half of Bering Sea by multibeam mapping, sediment profiling and dredge sampling in the framework of the joint German-Russian-U.S. American project BERING. Focus areas were A) the Chukotka-Beringian margins, once the possible site of Cretaceous arc volcanism prior to Eocene initiation of the Aleutian arc, B) the enigmatic Shirshov Ridge, separating the Komandorsky from the Aleutian Basin, C) Beta Rise, an area of anomalous high heat flow in the Komandorsky basin, D) the Volcanlogists Massif and adjacent volcanic and tectonic structures and E) the Komandorsky block, the westernmost section of the modern arc.....

Requirements and expectations of high-quality biomarkers for atopic dermatitis and psoriasis in 2021-a two-round Delphi survey among international experts

Background Chronic inflammatory skin diseases such as atopic dermatitis (AD) and psoriasis (PSO) present major challenges in health care. Thus, biomarkers to identify disease trajectories and response to treatments to improve the lives of affected individuals warrant great research consideration. The requirements that these biomarkers must fulfil for use as practical clinical tools have not yet been adequately investigated. Aim To identify the core elements of high-quality AD and PSO biomarkers to prepare recommendations for current biomarker research. Method A cross-sectional two-round Delphi survey was conducted from August to October 2019 and October to November 2020. All participants were members of the BIOMAP project, an EU-funded consortium of clinicians, researchers, patient organizations and pharmaceutical industry partners. The first round consisted of three open-ended questions. Responses were qualitatively analysed, and 26 closed statements were developed. For the second round, 'agreement' was assumed when the responses of >= 70% of the participants were >= 5 points on a 7-point Likert scale for each statement. Priority classification was based on mean scores (60th percentile = high). Results Twenty-one and twenty-six individuals participated in rounds one and two, respectively. From 26 statements that were included in round 2, 18 achieved agreement (8 concerning the performance, 8 for the purpose and 2 on current obstacles). Seven statements were classified as high priority, e.g. those concerning reliability, clinical validity, a high positive predictive value, prediction of the therapeutic response and disease progression. Another seven statements were assigned medium priority, e.g. those about analytical validity, prediction of comorbidities and therapeutic algorithm. Low priority included four statements, like those concerning cost effectiveness and prediction of disease flares. Conclusion The core requirements that experts agreed on being essential for high-quality AD and PSO biomarkers require rapid validation. Biomarkers can therefore be assessed based on these prioritized requirements.Peer reviewe

SYMptom monitoring with Patient-Reported Outcomes using a web application among patients with Lung cancer in the Netherlands (SYMPRO-Lung):Study protocol for a stepped-wedge randomised controlled trial

Introduction Lung cancer and its treatment cause a wide range of symptoms impacting the patients’ health-related quality of life (HRQoL). The use of patient-reported outcomes (PRO) to monitor symptoms during and after cancer treatment has been shown not only to improve symptom management but also to improve HRQoL and overall survival (OS). Collectively, these results favour implementation of PRO-symptom monitoring in daily clinical care. However, these promising outcomes have been obtained under trial conditions in which patients were selected based on stringent inclusion criteria, and in countries with a dissimilar healthcare system than in the Netherlands. The primary aim of the SYMptom monitoring with Patient-Reported Outcomes using a web application among patients with Lung cancer in the Netherlands (SYMPRO-Lung) study is to evaluate the effect of PRO-symptom monitoring during and after lung cancer treatment on HRQoL in daily clinical practice. Secondary objectives include assessing the effect of PRO-symptom monitoring on progression-free survival, OS, the incidence and grade of PRO symptoms, medication adherence, implementation fidelity and cost-effectiveness. Methods and analysis The SYMPRO-Lung study is a prospective, multicentre trial with a stepped wedge cluster randomised design. Study participants (n=292 intervention, n=292 controls) include patients with lung cancer (stages I–IV) starting treatment with surgery, systemic treatment, targeted treatment and/or radiotherapy. Every participating centre will consecutively switch from the control period to the intervention period, in which patients report their symptoms weekly via an online tool. In the intervention group, we evaluate two alert approaches: the active and reactive approach. If the symptoms exceed a predefined threshold, an alert is sent to the healthcare provider (active approach) or to the patient (reactive approach). Both the control and intervention group complete HRQoL questionnaires at 4 time points: at baseline, 15 weeks, 6 months and 1-year post treatment). Differences in HRQoL between the groups will be compared using linear mixed modelling analyses, accounting for within-centre clustering, potential time effects and confounding. Ethics and dissemination The study protocol was approved by the Institutional Review Board and the Medical Ethics Committee of the Amsterdam UMC (under number NL 68440.029.18) and the institutional review boards of the participating study sites. The dissemination of the results will be conducted through publication in peer-reviewed journals and through scientific conferences. Trial registration number Trial register identifier: Netherlands Trial register Trial NL7897. Date of registration: 24 July 2019. https://www.trialregister.nl/trial/7897

High-K volcanism in the Afyon region, western Turkey: from Si-oversaturated to Si-undersaturated volcanism

Volcanic rocks of the Afyon province (eastern part of western Anatolia) make up a multistage potassic and ultrapotassic alkaline series dated from 14 to 12 Ma. The early-stage Si-oversaturated volcanic rocks around the Afyon city and further southward are trachyandesitic volcanic activity (14.23 ± 0.09 Ma). Late-stage Si-undersaturated volcanism in the southernmost part of the Afyon volcanic province took place in three episodes inferred from their stratigraphic relationships and ages. Melilite– leucitites (11.50 ± 0.03 Ma), spotted rachyandesites, tephryphonolites and lamproites (11.91 ± 0.13 Ma) formed in the first episode; trachyandesites in the second episode and finally phonotephrites, phonolite, basaltic trachyandesites and nosean-bearing trachyandesites during the last episode. The parameter Q [normative q-(ne + lc + kls + ol)] of western Anatolia volcanism clearly decreased southward with time becoming zero in the time interval 10–15 Ma. The magmatism experienced a sudden change in the extent of Si saturation after 14 Ma, during late-stage volcanic activity of Afyon volcanic province at around 12 Ma, though there was some coexistence of Si-oversaturated and Si-undersaturated magmas during the whole life of Afyon volcanic province

The tumour microenvironment shapes dendritic cell plasticity in a human organotypic melanoma culture

Contains fulltext : 220729.pdf (publisher's version ) (Open Access)The tumour microenvironment (TME) forms a major obstacle in effective cancer treatment and for clinical success of immunotherapy. Conventional co-cultures have shed light onto multiple aspects of cancer immunobiology, but they are limited by the lack of physiological complexity. We develop a human organotypic skin melanoma culture (OMC) that allows real-time study of host-malignant cell interactions within a multicellular tissue architecture. By co-culturing decellularized dermis with keratinocytes, fibroblasts and immune cells in the presence of melanoma cells, we generate a reconstructed TME that closely resembles tumour growth as observed in human lesions and supports cell survival and function. We demonstrate that the OMC is suitable and outperforms conventional 2D co-cultures for the study of TME-imprinting mechanisms. Within the OMC, we observe the tumour-driven conversion of cDC2s into CD14(+) DCs, characterized by an immunosuppressive phenotype. The OMC provides a valuable approach to study how a TME affects the immune system

Exploratory 7-Tesla magnetic resonance spectroscopy in Huntington’s disease provides in vivo evidence for impaired energy metabolism

Huntington’s disease (HD) is a neurodegenerative genetic disorder that affects the brain. Atrophy of deep grey matter structures has been reported and it is likely that underlying pathologic processes occur before, or in concurrence with, volumetric changes. Measurement of metabolite concentrations in these brain structures has the potential to provide insight into pathological processes. We aim to gain understanding of metabolite changes with respect to the disease stage and pathophysiological changes. We studied five brain regions using magnetic resonance spectroscopy (MRS) using a 7-Tesla MRI scanner. Localized proton spectra were acquired to obtain six metabolite concentrations. MRS was performed in the caudate nucleus, putamen, thalamus, hypothalamus, and frontal lobe in 44 control subjects, premanifest gene carriers and manifest HD. In the caudate nucleus, HD patients display lower NAA (p = 0.009) and lower creatine concentration (p = 0.001) as compared to controls. In the putamen, manifest HD patients show lower NAA (p = 0.024), lower creatine concentration (p = 0.027), and lower glutamate (p = 0.013). Although absolute values of NAA, creatine, and glutamate were lower, no significant differences to controls were found in the premanifest gene carriers. The lower concentrations of NAA and creatine in the caudate nucleus and putamen of early manifest HD suggest deficits in neuronal integrity and energy metabolism. The changes in glutamate could support the excitotoxicity theory. These findings not only give insight into neuropathological changes in HD but also indicate that MRS can possibly be applied in future clinical trails to evaluate medication targeted at specific metabolic processes

Convolutional neural networks for transient candidate vetting in large-scale surveys

Current synoptic sky surveys monitor large areas of the sky to find variable and transient astronomical sources. As the number of detections per night at a single telescope easily exceeds several thousand, current detection pipelines make intensive use of machine learning algorithms to classify the detected objects and to filter out the most interesting candidates. A number of upcoming surveys will produce up to three orders of magnitude more data, which renders high-precision classification systems essential to reduce the manual and, hence, expensive vetting by human experts. We present an approach based on convolutional neural networks to discriminate between true astrophysical sources and artefacts in reference-subtracted optical images. We show that relatively simple networks are already competitive with state-of-the-art systems and that their quality can further be improved via slightly deeper networks and additional pre-processing steps – eventually yielding models outperforming state-of-the-art systems. In particular, our best model correctly classifies about 97.3 per cent of all ‘real’ and 99.7 per cent of all ‘bogus’ instances on a test set containing 1942 ‘bogus’ and 227 ‘real’ instances in total. Furthermore, the networks considered in this work can also successfully classify these objects at hand without relying on difference images, which might pave the way for future detection pipelines not containing image subtraction steps at all